[alaskayorkie]

Interesting question. Thanks for posting.

I wish Eddie had a tail so I can tell what he's thinking sooner! Generally, his is straight out or mildly down. It goes up when he's curious or mad. It wags like a dickens when he's happy.

I just Googled hoping to find pictures of what dog's tail position means, and while I didn't find that I thought this explanation on wikianswers.com was interesting.

Most people have heard a dog wags his tail when he is happy. This is actually only partial correct. A dog wags their tail due to feeling conflicting emotions at the same time. An example of this would be feeling happy and nervous together. These conflicting emotions manifest into the body language of wagging their tail. Tail wagging starts from the time they are born and are nursing on their mother, they are content to be feeding but instinctively anxious to be feeding so close to another dog, in this case their litter mate. When a dog sees his master he is happy to see him but because he is submissive to his master he is wary not to upset. When a dog see a stranger walking up to him he can be excited to see some one but very nervous because he does not know them.